The invention discloses an automatic filter membrane folding device and a use method. The automatic filter membrane folding device comprises a shell, a rotary table and a power device. The power device drives the rotary table to rotate, a fan-shaped fixed blade is fixed to the top of the rotary table, and a membrane pressing and fixing device is arranged on the arc side of the fan-shaped fixed blade. A transmission shaft of a fan-shaped clamping piece is movably connected with one right-angle edge of the fan-shaped fixed blade. A transmission shaft of a semicircular clamping piece is movably connected with the other right-angle edge of the fan-shaped fixed blade. Two circles of rails are arranged on the shell, the inner rail is matched with a transmission wheel I and a transmission wheel II, and the transmission wheel I and the transmission wheel II are arranged at the tail end of the transmission shaft of the fan-shaped clamping piece and the tail end of the transmission shaft of the semicircular clamping piece respectively. The outer rail is matched with a transmission wheel III located at the tail end of a film pressing transmission shaft. The other end of the film pressing transmission shaft is connected with the film pressing and fixing device. Upper teeth and lower teeth are arranged on the two circles of rails. The automatic filter membrane folding device rotates through the power device, full-automatically folds filter membranes, does not need manual folding, is convenient and quick to use, and improves work efficiency.